Fluid permeable heater assembly with cap

ABSTRACT

A fluid permeable heater assembly for an aerosol-generating system includes a cap and a substantially flat electrically conductive and fluid permeable heating element. The cap includes a hollow body with a first cap opening and a second cap opening. The first cap opening is opposite to the second cap opening. The heating element is configured to vaporize aerosol-forming substrate. The heating element is mounted on the cap, such that the heating element extends across the first cap opening. A cartridge for an aerosol-generating system includes the heater assembly, a liquid storage portion, a mouth piece, and a retainer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/658,881, filed Jul. 25, 2017, which is a continuation and claimspriority to PCT/EP2017/065063, filed Jun. 20, 2017, and further claimspriority under 35 U.S.C. § 119 to European Patent Application No.16180958.7, filed Jul. 25, 2016, the entire contents of each of whichare incorporated herein by reference.

BACKGROUND Field

Example embodiments relate to aerosol-generating systems. At least oneexample embodiment relates to heater assemblies for aerosol-generatingsystems in which the aerosol-forming substrate is liquid and vaporized.

Description of Related Art

Handheld electrically operated aerosol-generating system may include adevice portion comprising a battery and control electronics, a cartridgeportion comprising a supply of aerosol-forming substrate held in aliquid storage portion, and an electrically operated heater assemblyacting as a vaporizer. The heater assembly may comprise a fluidpermeable heating element that is in contact with a capillary mediumlike an elongated wick soaked in the liquid aerosol-forming substrateheld in the liquid storage portion. The cartridge portion may comprisenot only the supply of aerosol-forming substrate and an electricallyoperated heater assembly, but also a mouthpiece.

A heater assembly with a fluid permeable heating element may have afragile structure.

SUMMARY

At least one example embodiment relates to a heater assembly for anaerosol-generating system.

In at least one example embodiment, a heater assembly is fluidpermeable. The heater assembly comprising a cap and a heating element.The cap includes a hollow body having a first cap opening and a secondcap opening. The first cap opening is opposite the second cap opening.The cap is integrally formed. The cap also includes a holder including aholder opening. The holder is configured to cover the first cap openingsuch that the holder opening superposes with at least a portion of thefirst cap opening. The heating element is a substantially flatelectrically conductive and fluid permeable heating element. The heatingelement is configured to vaporize an aerosol-forming substrate. Theheating element is mounted on the holder such that the heating elementextends across the first cap opening.

In at least one example embodiment, the heater assembly includes a hostmaterial piece configured to retain the aerosol-forming substrate. Atleast a portion of the host material piece is arranged in the hollowbody between the first cap opening and the second cap opening. The hostmaterial piece is substantially a same size and a same shape as aninterior space of the hollow body. An interior space of the hollow bodyhas a substantially cylindrical shape. The host material piece is atleast partially in contact with the heating element.

In at least one example embodiment, the heater assembly includes atransport material piece configured to transport the aerosol-formingsubstrate from the host material piece to the heating element. Thetransport material piece is in contact with the heating element. Thetransport material piece is between the heating element and the hostmaterial piece. The heating element is mounted on the holder.

In at least one example embodiment, the transport material piece is inthe holder opening. The transport material piece has substantially asame size and a same shape as the holder opening.

In at least one example embodiment, the heating element comprises: amesh including at least two electrically conductive contact areas. Eachof the at least two electrically conductive contact areas are positionedat an edge area of the heating element. The mesh extends across at leasta portion of the first cap opening.

In at least one example embodiment, the at least two electricallyconductive contact areas are at a dense area of the heating element.

At least one example embodiment relates to a cartridge for anaerosol-generating system.

In at least one example embodiment, a cartridge for anaerosol-generating system comprises a heater assembly. The heaterassembly includes a cap including a hollow body having a first capopening and a second cap opening. The first cap opening is opposite thesecond cap opening. The cap is integrally formed. The cap also includesa holder including a holder opening. The holder is configured to coverthe first cap opening such that the holder opening superposes with atleast a portion of the first cap opening. The heater assembly alsoincludes a heating element. The heating element is a substantially flatelectrically conductive and fluid permeable heating element. The heatingelement is configured to vaporize an aerosol-forming substrate. Theheating element is mounted on the holder such that the heating elementextends across the first cap opening. The cartridge also includes astorage portion configured to store an aerosol-forming substrate and aretainer configured to retain the heater assembly and configured toretain the heater assembly in contact with the storage portion.

In at least one example embodiment, the cartridge also includes a mouthpiece configured to hold the storage portion.

At least one example embodiment relates to an aerosol-generating system.

In at least one example embodiment, an aerosol-generating system,comprises a main unit and a cartridge. The cartridge includes a heaterassembly. The heater assembly includes a cap. The cap includes a hollowbody and a holder. The hollow body has a first cap opening and a secondcap opening. The first cap opening is opposite the second cap opening.The cap is integrally formed. The holder includes a holder opening. Theholder is configured to cover the first cap opening such that the holderopening superposes with at least a portion of the first cap opening. Theheater assembly also includes a heating element. The heating element isa substantially flat electrically conductive and fluid permeable heatingelement. The heating element is configured to vaporize anaerosol-forming substrate. The heating element is mounted on the holdersuch that the heating element extends across the first cap opening. Thecartridge also includes a storage portion configured to store anaerosol-forming substrate, and a retainer configured to retain theheater assembly and configured to retain the heater assembly in contactwith the storage portion. The cartridge is removably coupled to the mainunit.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiment will now be described, by way of example only, withreference to the accompanying drawings.

FIG. 1A is a perspective top side view of a heater assembly inaccordance with at least one example embodiment.

FIG. 1B is a perspective bottom side view of a heater assembly inaccordance with at least one example embodiment.

FIG. 1C is an exploded perspective view of a heater assembly inaccordance with at least one example embodiment.

FIG. 2A is a top view of a cap and a holder according to at least oneexample embodiment.

FIG. 2B is a cross-sectional view of the cap and the holder along lineA-A of FIG. 2A according to at least one example embodiment.

FIG. 2C is a cross-sectional view of the cap and the holder along lineB-B of FIG. 2A according to at least one example embodiment.

FIG. 2D is a perspective view of a cap and a holder in accordance withat least one example embodiment.

FIG. 3 is a top side view of a holder, a heating element, and contactareas in accordance with at least one example embodiment.

FIG. 4 is a top side view of a mesh having two different mesh densitiesin accordance with at least one example embodiment.

FIG. 5 is a top side view of a mesh strip for manufacturing a mesh inaccordance with at least one example embodiment.

FIG. 6 is an exploded perspective view of a cartridge for anaerosol-generating system in accordance with at least one exampleembodiment.

FIG. 7 is a schematic view of an aerosol-generating system in accordancewith at least one example embodiment.

DETAILED DESCRIPTION

Example embodiments will become more readily understood by reference tothe following detailed description of the accompanying drawings. Exampleembodiments may, however, be embodied in many different forms and shouldnot be construed as being limited to the example embodiments set forthherein. Rather, these example embodiments are provided so that thisdisclosure will be thorough and complete. Like reference numerals referto like elements throughout the specification.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises,” “comprising,”“includes,” and/or “including,” when used in this specification, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on”, “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one element, component, region, layer or section fromanother region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings set forth herein.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the example term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

Example embodiments are described herein with reference to cross-sectionillustrations that are schematic illustrations of idealized embodiments(and intermediate structures). As such, variations from the shapes ofthe illustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, these example embodimentsshould not be construed as limited to the particular shapes of regionsillustrated herein, but are to include deviations in shapes that result,for example, from manufacturing. For example, an implanted regionillustrated as a rectangle will, typically, have rounded or curvedfeatures and/or a gradient of implant concentration at its edges ratherthan a binary change from implanted to non-implanted region. Likewise, aburied region formed by implantation may result in some implantation inthe region between the buried region and the surface through which theimplantation takes place. Thus, the regions illustrated in the figuresare schematic in nature and their shapes are not intended to illustratethe actual shape of a region of a device and are not intended to limitthe scope of this disclosure.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art. It will be further understood that terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and this specification and will not beinterpreted in an idealized or overly formal sense unless expressly sodefined herein.

Unless specifically stated otherwise, or as is apparent from thediscussion, terms such as “processing” or “computing” or “calculating”or “determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical, electronicquantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

At least one example embodiment relates to a fluid permeable heaterassembly for an aerosol-generating system. The heater assembly comprisesa cap. The cap comprises a hollow body with a first and a second capopening. The first cap opening is opposite to the second cap opening,and a substantially flat electrically conductive and fluid permeableheating element. The heating element is configured to vaporizeaerosol-forming substrate. The heating element is mounted on the capsuch that the heating element extends across the first cap opening.

A cap with a hollow body may be attached to the heating element toimprove stability of the heating element and to provide guidance for acapillary medium that may be arranged in the hollow body of the cap. Theuse of a cap may simplify the manufacturing of the heater assembly andmay improve the rigidity of the heater assembly.

The cap may cover a filled cartridge.

As used herein, “substantially flat” means formed initially in a singleplane and not wrapped around or other conformed to fit a curved or othernon-planar shape. As used herein, “electrically conductive” means formedfrom a material having a resistivity of about 1×10⁻⁴ Ohm meter, or less.As used herein, “electrically insulating” means formed from a materialhaving a resistivity of about 1×10⁴ Ohm meter or more. As used herein,“fluid permeable” in relation to a heater assembly means that theaerosol-forming substrate, in a gaseous phase and possibly in a liquidphase, can readily pass through the heating element of the heaterassembly.

The heater assembly comprises a cap formed from a material with a highthermal decomposition temperature and that is able to tolerate rapidtemperature changes. The heating element is supported on the cap. In atleast one example embodiment, the cap is molded from plastic granules.The plastic granules may be of polyether ether ketone (PEEK),liquid-crystal polymers (LCP) or any other polymer material. In at leastone example embodiment, the cap material is over-molded on the undersideof the heating element. In at least one example embodiment, the cap ismade of VICTREX PEEK via over-molding on a mesh strip. The underside ofthe heating element is oriented towards the first cap opening. The capmay be over molded onto the underside of the heating, such that nofurther mounting material, such as terminals, is required to fix theheating element on the cap.

In at least one example embodiment, the cap has a size sufficient todistance the liquid storage portion from the heating element by adistance of at least about 1.5 millimeters, or from about 3 millimetersto about 6 millimeters in order to provide a sufficient temperature dropacross the cap. In at least one example embodiment, the liquid storageportion can be made from a more cost efficient material with a lowerthermal decomposition temperature, such as for example polyethylene orpolypropylene.

The heater assembly further comprises a substantially flat heatingelement allowing for simple manufacture. Geometrically, the term“substantially flat” electrically conductive heating element is used torefer to an electrically conductive arrangement of filaments that is inthe form of a substantially two dimensional topological manifold. Thus,the substantially flat electrically conductive heating element extendsin two dimensions along a surface substantially more than in a thirddimension. In particular, the dimensions of the substantially flatheating element in the two dimensions within the surface is at leastfive times larger than in the third dimension, normal to the surface. Anexample of a substantially flat heating element is a structure betweentwo substantially imaginary parallel surfaces, wherein the distancebetween these two imaginary surfaces is substantially smaller than theextension within the surfaces. In some embodiments, the substantiallyflat heating element is planar. In other embodiments, the substantiallyflat heating element is curved along one or more dimensions, for exampleforming a dome shape or bridge shape.

The term “filament” is used throughout the specification to refer to anelectrical path arranged between two electrical contacts. A filament mayarbitrarily branch off and diverge into several paths or filaments,respectively, or may converge from several electrical paths into onepath. A filament may have a round, square, flat or any other form ofcross-section. A filament may be arranged in a straight or curvedmanner.

The term “heating element” is used throughout the specification to referto an arrangement of one or a plurality of filaments. The heatingelement may be an array of filaments, for example arranged parallel toeach other. The heating element is fluid permeable. The heating elementmay be cut so as to provide open areas when mounting the heating elementacross the first cap opening. In at least one example embodiment, theopen areas are manufactured by cutting bevelled window slots out of eachside of the heating element. In at least one example embodiment, thefilaments may form a mesh. The mesh may be woven or non-woven. The meshmay be formed using different types of weave or lattice structures.Alternatively, the electrically conductive heating element consists ofan array of filaments arranged parallel to one another. The mesh, arrayor fabric of electrically conductive filaments may also be characterizedby its ability to retain liquid.

In at least one example embodiment, a substantially flat heating elementmay be constructed from a wire that is formed into a wire mesh. In atleast one example embodiment, the mesh has a plain weave design. In atleast one example embodiment, the heating element is a wire grill madefrom a mesh strip.

The electrically conductive filaments may define interstices between thefilaments and the interstices may have a width of about 10 micrometersto about 100 micrometers. In at least one example embodiment, thefilaments give rise to capillary action in the interstices, so that inuse, liquid to be vaporized is drawn into the interstices, increasingthe contact area between the heating element and the liquidaerosol-forming substrate.

The electrically conductive filaments may form a mesh of size between 60and 240 filaments per centimeter (+/−10 percent). In at least oneexample embodiment, the mesh density is between 100 and 140 filamentsper centimeter (+/−10 percent). In at least one example embodiment, themesh density is approximately 115 filaments per centimeter. The width ofthe interstices may range from about 100 micrometers to about 25micrometers, or from about 80 micrometers to about 70 micrometers. In atleast one example embodiment, the width of the interstices may be about74 micrometers. The percentage of open area of the mesh, which is theratio of the area of the interstices to the total area of the mesh mayrange from about 40 percent to about 90 percent, from about 85 percentto about 80 percent, or may be about 82 percent. Throughout thisspecification, the density of such a mesh is referred to as “first meshdensity”.

Additionally, the mesh may have one or more sections with increased meshdensity, referred to as “second mesh density”, where the intersticesbetween the filaments are below about 5 micrometers, below about 2micrometers, or be about 1 micrometer. The one or more sections of themesh with increased mesh density are referred to as “dense areas”throughout this specification.

The electrically conductive filaments may have a diameter ranging fromabout 8 micrometers to about 100 micrometers, from about 10 micrometersto about 50 micrometers, or from about 12 micrometers to about 25micrometers. The filaments may have a round cross section or may have aflattened cross-section.

The area of the mesh, array or fabric of electrically conductivefilaments may be small, for example less than or equal to about 50square millimeters, less than or equal to about 25 square millimeters,or about 15 square millimeters. The size is chosen such to incorporatethe heating element into a handheld system. Sizing of the mesh, array orfabric of electrically conductive filaments less or equal than about 50square millimeters reduces the amount of total power required to heatthe mesh, array or fabric of electrically conductive filaments whilestill ensuring sufficient contact of the mesh, array or fabric ofelectrically conductive filaments to the liquid aerosol-formingsubstrate. The mesh, array or fabric of electrically conductivefilaments may, for example, be rectangular and have a length rangingfrom about 2 millimeters to about 10 millimeter and a width ranging fromabout 2 millimeters to about 10 millimeters. In at least one exampleembodiment, the mesh has dimensions of about 5 millimeters by about 3millimeters. The mesh or array of electrically conductive filaments maycover an area of about 30 percent to about 90 percent of the open areaof the first cap opening across which the heating element extends. In atleast one example embodiment, the mesh or array of electricallyconductive filaments covers an area of about 50 percent to about 70percent of the open area of the first cap opening. In at least oneexample embodiment, the mesh or array of electrically conductivefilaments covers an area of about 55 percent to about 65 percent of theopen area of the first cap opening.

The filaments of the heating element may be formed from any materialwith suitable electrical properties. Suitable materials include but arenot limited to: semiconductors such as doped ceramics, electrically“conductive” ceramics (such as, for example, molybdenum disilicide),carbon, graphite, metals, metal alloys and composite materials made of aceramic material and a metallic material. Such composite materials maycomprise doped or undoped ceramics. Examples of suitable doped ceramicsinclude doped silicon carbides. Examples of suitable metals includetitanium, zirconium, tantalum and metals from the platinum group.

Examples of suitable metal alloys include stainless steel, constantan,nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-,niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-and iron-containing alloys, and super-alloys based on nickel, iron,cobalt, stainless steel, Timetal®, iron-aluminum based alloys andiron-manganese-aluminum based alloys. Timetal® is a registered trademark of Titanium Metals Corporation. The filaments may be coated withone or more insulators. The materials for the electrically conductivefilaments are stainless steel and graphite. For example, the materialsmay include 300 series stainless steel like AISI 304, 316, 304L, 316L.Additionally, the electrically conductive heating element may comprisecombinations of the above materials. A combination of materials may beused to improve the control of the resistance of the substantially flatheating element. For example, materials with a high intrinsic resistancemay be combined with materials with a low intrinsic resistance so as tocontrol price. A substantially flat filament arrangement with increasedresistance may reduce parasitic losses. High resistivity heaters mayallow more efficient use of battery energy.

In at least one example embodiment, the filaments are made of wire. Inat least one example embodiment, the wire is made of metal, such asstainless steel.

The electrical resistance of the mesh, array or fabric of electricallyconductive filaments of the heating element may be about 0.3 Ohms toabout 4 Ohms. In at least one example embodiment, the electricalresistance is equal or greater than about 0.5 Ohms. In at least oneexample embodiment, the electrical resistance of the mesh, array orfabric of electrically conductive filaments is about 0.6 Ohms to about0.8 Ohms, or about 0.68 Ohms. The electrical resistance of the mesh,array or fabric of electrically conductive filaments is at least anorder of magnitude, or at least two orders of magnitude, greater thanthe electrical resistance of electrically conductive contact areas. Thisensures that the heat generated by passing current through the heatingelement is localized to the mesh or array of electrically conductivefilaments. The system may have a low overall resistance for the heatingelement if the system is powered by a battery. A low resistance, highcurrent system allows for the delivery of high power to the heatingelement. This allows the heating element to heat the electricallyconductive filaments to a desired temperature quickly.

The hollow body of the cap may be configured to hold a capillary medium.In at least one example embodiment, the heater assembly comprises a hostmaterial piece made from the capillary medium for retaining the liquidaerosol-forming substrate. At least a portion of the host material piecemay be arranged in the hollow body between the first and the second capopening.

The cap and the host material piece may be sized to have across-sectional area of approximately the same size. As used here,approximately the same size means that a cross-sectional area of the capcomprising the first cap opening may be up to 30 percent smaller orlarger than the capillary material. The shape of the interior space ofthe hollow body of the cap may also be similar to the shape of thecapillary material such that the assembly and the material substantiallyoverlap. In at least one example embodiment, the host material piece issubstantially the same size and shape as the interior space of thehollow body. In at least one example embodiment, the interior space ofthe hollow body is substantially of cylindrical shape. The volume of theinterior space of the hollow body may be about 50 cubic millimetres toabout 500 cubic millimeters, about 100 cubic millimeters to about 250cubic millimeters, or about 150 cubic millimeters.

The host material piece may be provided at least partially in contactwith the heating element. When the assembly and the material aresubstantially similar in size and shape, manufacturing can be simplifiedand the robustness of the manufacturing process improved.

In at least one example embodiment, the heater assembly comprises atransport material piece made from a capillary medium for transportingliquid aerosol-forming substrate from the host material piece to theheating element. The transport material piece may be provided in contactwith the heating element. In at least one example embodiment, thetransport material piece is arranged between the heating element and thehost material piece. In this case, the host material is not in directcontact with the heating element.

The transport material piece may be made of a material configured toguarantee that there is liquid aerosol-forming substrate in contact withat least a portion of the surface of the heating element that extendsacross the first cap opening. The transport material piece may be incontact with the electrically conductive filaments. The transportmaterial piece may extend into interstices between the filaments. Theheating element may draw liquid aerosol-forming substrate into theinterstices by capillary action. In at least one example embodiment, thetransport material piece is in contact with the electrically conductivefilaments over substantially the entire extent of the open area of thefirst cap opening.

A capillary material is a material that actively conveys liquid from oneend of the material to another. The capillary material may be oriented,directly or indirectly via another capillary medium, in contact with aliquid storage portion to convey liquid aerosol-forming substratetowards the heating element.

The capillary material may include even more than two capillarymaterials including one or more layers of the capillary materialdirectly in contact with the mesh, array or fabric of electricallyconductive filaments of the heating element in order to promote aerosolgeneration.

The capillary material may have a fibrous or spongy structure. Thecapillary material comprises a bundle of capillaries. For example, thecapillary material may comprise a plurality of fibres or threads orother fine bore tubes. The fibres or threads may be generally aligned toconvey liquid aerosol-forming substrate towards the heating element.Alternatively, the capillary material may comprise sponge-like orfoam-like material. The structure of the capillary material forms aplurality of small bores or tubes, through which the liquidaerosol-forming substrate can be transported by capillary action. Thecapillary material may comprise any suitable material or combination ofmaterials. Examples of suitable materials are a sponge or foam material,ceramic- or graphite-based materials in the form of fibres or sinteredpowders, foamed metal or plastics material, a fibrous material, forexample made of spun or extruded fibres, such as cellulose acetate,polyester, or bonded polyolefin, polyethylene, terylene or polypropylenefibres, nylon fibres or ceramic. The capillary material may have anysuitable capillarity and porosity so as to be used with different liquidphysical properties. The liquid aerosol-forming substrate has physicalproperties, including but not limited to viscosity, surface tension,density, thermal conductivity, boiling point and vapour pressure, whichallow the liquid aerosol-forming substrate to be transported through thecapillary medium by capillary action.

At least one of the capillary materials may be of sufficient volume inorder to ensure that a minimal amount of liquid aerosol-formingsubstrate is present in said capillary material to prevent “dryheating”, which occurs if insufficient liquid aerosol-forming substrateis provided to the capillary material in contact with the mesh, array orfabric of electrically conductive filaments. A minimum volume of saidcapillary material may be provided in order to allow for about 20 toabout 40 puffs. An average volume of liquid aerosol-forming substratevolatilized during a puff of a length of about 1 second to about 4seconds about 1 to milligram to about 4 milligrams of liquidaerosol-forming substrate. Thus, providing at least one capillarymaterial having a volume to retain about 20 milligrams to about 160milligrams of the liquid aerosol-forming substrate may reduce and/orsubstantially prevent the dry heating.

The cap may contain two or more different capillary materials, whereinthe transport material piece, in contact with the heating element, mayhave a higher thermal decomposition temperature and the host materialpiece, in contact with the transport material piece, but not in contactwith the heating element, may have a lower thermal decompositiontemperature. The transport material piece effectively acts as a spacerseparating the heating element from the host material piece so that thehost material piece is not exposed to temperatures above its thermaldecomposition temperature. As used herein, “thermal decompositiontemperature” means the temperature at which a material begins todecompose and lose mass by generation of gaseous by products. The hostmaterial piece may occupy a greater volume than the transport materialpiece and may hold more aerosol-forming substrate than the transportmaterial piece. The host material piece may have superior wickingperformance as compared to the transport material piece. The hostmaterial piece may be cheaper than the transport material piece. Thehost material piece may be polypropylene.

The transport material piece may separate the heating element from thehost material piece by a distance of at least about 0.5 millimeter,about 0.5 millimeter to about 2 millimeters, or about 0.75 millimeter inorder to provide a sufficient temperature drop across the transportmaterial piece.

In at least one example embodiment, the cap comprises a holder with aholder opening. The holder may be a planar disk covering at least thefirst cap opening and having a thickness of about 0.25 millimeter toabout 5 millimeters, about 0.5 millimeter to about 2.5 millimeters, orabout 0.8 millimeter. The holder opening may have a size of about 10square millimeters to about 50 square millimeters, about 20 squaremillimeters to about 30 square millimeters, or about 25 squaremillimeters. The holder may cover the first cap opening such that theholder opening coincides with at least a portion of the first capopening. The heating element may be mounted on the holder. A surface ofthe holder is in contact with the heating element and represents acontact area that enlarges the contact area as compared to a cap withouta holder. The holder reduces the size of the first cap opening to thesize of the holder opening. Enlarging the contact area between holderand heating element may improve rigidity of the heater assembly and mayease the assembly thereof. In at least one example embodiment, the capincluding the holder is over-molded on the underside of the heatingelement.

In at least one example embodiment, the cap is integrally formed. Theintegrally formed cap may include the holder.

In at least one example embodiment, the transport material piece isarranged in the holder opening. In at least one example embodiment, thetransport material piece has substantially the same size and shape asthe holder opening.

In at least one example embodiment, the cap comprises at least one wallforming the hollow body that extends from the holder. In at least oneexample embodiment, the wall extends perpendicular to the holder. In atleast one example embodiment, the wall extends perpendicular to a planeof the heating element.

The heating element may have at least two electrically conductivecontact areas. The electrically conductive contact areas may bepositioned at an edge area of the heating element.

In at least one example embodiment, the at least two electricallyconductive contact areas are each positioned at a dense area of theheating element. The electrically conductive contact areas may bepositioned on extremities of the heating element. An electricallyconductive contact area may be fixed directly to the electricallyconductive filaments. An electrically conductive contact area maycomprise a tin patch. Alternatively, an electrically conductive contactarea may be integral with the electrically conductive filaments.

According to at least one example embodiment there is provided acartridge for an aerosol-generating system. The cartridge comprises theheater assembly, a liquid storage portion for storing liquidaerosol-forming substrate, and a retainer for retaining the componentsof the heater assembly and for keeping the heater assembly in contactwith the liquid storage portion.

In at least one example embodiment, the cartridge comprises a mouthpiece configured to hold the liquid storage portion.

In at least one example embodiment, a host material piece is arranged inthe interior space of the hollow body of the cap of the heater assembly.A transport material piece may be arranged in the holder opening of aholder that covers the first cap opening. The cap acts as a rigidhousing for the transport material piece and the host material piece.The retainer keeps the heater assembly in contact with the liquidstorage portion via the transport material piece and the host materialpiece. In at least one example embodiment, a proximal end of the wall ofthe cap adjoins the holder and a distal end of the wall of the capengages the liquid storage portion.

The cartridge may be a disposable article to be replaced with a newcartridge once the liquid storage portion of the cartridge is empty orbelow a minimum volume threshold. In at least one example embodiment,the cartridge is pre-loaded with liquid aerosol-forming substrate. Thecartridge may be refillable.

The cartridge and its components may be made of thermoplastic polymers,as polyether ether ketone (PEEK).

At least one example embodiment relates to an aerosol-generating system,comprising a main unit and the cartridge. The cartridge is removablycoupled to the main unit.

As used herein, the cartridge being “removably coupled” to the main unitmeans that the cartridge and the main unit can be coupled and uncoupledfrom one another without significantly damaging either the main unit orthe cartridge.

The aerosol-generating system may further comprise electric circuitryconnected to the heater assembly and to an electrical power source, theelectric circuitry configured to monitor the electrical resistance ofthe heater assembly or of one or more filaments of the heater assembly,and to control the supply of power to the heater assembly dependent onthe electrical resistance of the heater assembly or the one or morefilaments.

The electric circuitry may comprise a microprocessor, which may be aprogrammable microprocessor. The electric circuitry may comprise furtherelectronic components. The electric circuitry may be configured toregulate a supply of power to the heater assembly. Power may be suppliedto the heater assembly continuously following activation of the systemor may be supplied intermittently, such as on a puff-by-puff basis. Thepower may be supplied to the heater assembly in the form of pulses ofelectrical current.

The aerosol-generating system comprises a power supply, typically abattery, within the main body of the housing. As an alternative, thepower supply may be another form of charge storage device such as acapacitor. The power supply may require recharging and may have acapacity to allow for the continuous generation of aerosol for a periodof around six minutes or for a period that is a multiple of six minutes.In another example embodiment, the power supply may have sufficientcapacity to allow for a desired (or, alternatively predetermined) numberof puffs or discrete activations of the heater assembly.

In at least one example embodiment, the aerosol generating systemcomprises a housing. In at least one example embodiment, the housing iselongate. The housing may comprise any suitable material or combinationof materials. Examples of suitable materials include metals, alloys,plastics or composite materials containing one or more of thosematerials, or thermoplastics that are suitable for food orpharmaceutical applications, for example polypropylene, polyether etherketone (PEEK) and polyethylene. In at least one example embodiment, thematerial is light and non-brittle.

In at least one example embodiment, the aerosol-generating system isportable. The aerosol-generating system may have a size comparable to acigar or a cigarette. The aerosol-generating system may have a totallength ranging from about 30 millimeters to about 150 millimeters. Theaerosol-generating system may have an external diameter ranging fromabout 5 millimeters to about 30 millimeters.

The aerosol-forming substrate is a substrate configured to releasevolatile compounds that can form an aerosol. The volatile compounds maybe released by heating the aerosol-forming substrate.

The aerosol-forming substrate may comprise plant-based material. Theaerosol-forming substrate may comprise tobacco. The aerosol-formingsubstrate may comprise a tobacco-containing material containing volatiletobacco flavour compounds, which are released from the aerosol-formingsubstrate upon heating. The aerosol-forming substrate may alternativelycomprise a non-tobacco-containing material. The aerosol-formingsubstrate may comprise homogenized plant-based material. Theaerosol-forming substrate may comprise homogenized tobacco material. Theaerosol-forming substrate may comprise at least one aerosol-former. Theaerosol-forming substrate may comprise other additives and ingredients,such as flavourants.

According to at least one example embodiment, a method for manufacturinga fluid permeable heater assembly includes providing a substantiallyflat electrically conductive heating element, and over-molding a cap onedge areas of one side of the heating element. The cap comprises ahollow body with a first and a second cap opening. The first cap openingis opposite to the second cap opening. The heating element is mounted onthe cap such that the heating element extends across the first capopening.

The providing of a heating element may comprise providing a mesh strip.The mesh strip may comprise an alternating sequence of mesh sections ofa first mesh density and a second mesh density. Having sections of ahigher density may increase the stability of the mesh while handling it.

The providing the heating element may further comprise die cuttingbevelled window slots out of each side of a mesh section of the firstmesh density, and removing loose wires from the cut mesh sections of thefirst mesh density.

In at least one example embodiment, the first mesh density is lower thanthe second mesh density.

In at least one example embodiment, the step of over-molding of a cap onedge areas of one side of the heating element comprises pre-heatingplastic granules, injecting the plastic granules into a mold for makingthe cap, and over-molding the cap onto the underside of a mesh sectionof the second mesh density.

In at least one example embodiment, the over-molding a cap on edge areasof one side of the heating element further comprises cutting the heaterassembly off the mesh strip, and removing debris from the heaterassembly.

In at least one example embodiment, the cutting the heater assembly offthe mesh strip comprises die cutting a mesh off the mesh strip. Theheating element comprises the mesh, and the mesh is cut within a meshsection of the second mesh density such that the mesh comprises a meshsection of the first mesh density that is limited by mesh sections ofthe second mesh density on each of the two ends of the cut mesh.

In at least one example embodiment, the method for manufacturing a fluidpermeable heater assembly further comprises joining at least twoelectrically conductive contact areas each onto an edge area of theother side of the heating element.

The joining at least two electrically conductive contact areas each ontoan edge area of the other side of the heating element may compriseproviding a tin foil strip, cutting off tin foil patches from a tin foilstrip in a size that matches the shape and the size of the mesh sectionof the second mesh density, and compressing a tin foil patch onto themesh section of the second mesh density. The foil strip may be made of asofter material than the material of the heating element.

In at least one example embodiment, the method for manufacturing a fluidpermeable heater assembly further comprises inspecting the heaterassembly.

In at least one example embodiment, the inspecting the heater assemblycomprises transporting the heater assembly to inspection stations,measuring the electrical resistance of the heating element of themanufactured heater assembly, visually inspecting the heating elementfor correct wire count, clean cut-off of the mesh, correct meshintegrity, debris and tin foil attachment, and rejecting the heaterassembly if the heater assembly fails at least one of the expectedelectrical resistance of the heating element and the expected result ofthe visual inspection.

At least one example embodiment relates to an apparatus formanufacturing a fluid permeable heater assembly.

In order to manufacture a heater assembly comprising a cap and asubstantially flat electrically conductive heating element with a mesh,the apparatus for manufacturing a fluid permeable heater assembly maycomprise at least one of the following equipment units: a mesh stripbobbin feeding unit for providing a mesh strip, the mesh stripcomprising an alternating sequence of mesh sections of a first meshdensity and of a second mesh density, a tin foil strip bobbin feedingunit for providing a tin foil strip, a tin foil cutting station forindexing a length of tin foil to be positioned over the mesh section ofthe second mesh density and for cutting tin patches from the providedtin foil strip, a tin foil pressing station for compressing to join thetin patches onto the top surface of the mesh section of the second meshdensity, a mesh window cutting station for die cutting bevelled windowslots out of each side of a mesh section of the first mesh density, afirst cleaning station for removing loose wires from the cut meshsections of the first mesh density, small particles, dust, or debris bycleaning with air pressure and vacuuming the surfaces of the cut meshsections to remove debris, an injection molding machine for pre-heatingplastic granules and injecting the same into a mold for making the cap,a mesh injection over-molding tool (possibly having a single cavity orseveral cavities) for over-molding the cap onto the underside of themesh section of the second mesh density, a heater assembly cut-offstation for cutting the heater assembly off the mesh strip by diecutting a mesh off the mesh strip, the heating element comprising themesh, and the mesh being cut within a mesh section of the second meshdensity such that the mesh comprises a mesh section of the first meshdensity that is limited by mesh sections of the second mesh density oneach of the two ends of the cut mesh, a second cleaning station forremoving loose wires from the mesh by cleaning with air pressure andvacuuming the surfaces of the heater assembly to remove debris, atransfer unit for transporting the heater assembly to a heater assemblyinspection station, the heater assembly inspection station may comprisea heater assembly resistance measuring station, a heater assembly visioninspection station and a heater assembly rejection station, a meshstating pressure testing station, a heater assembly resistance measuringstation for measuring the electrical resistance of the mesh and the tinfoil strip of the manufactured heater assembly, a heater assembly visioninspection for visually inspecting the heater assembly, and a heaterassembly rejection station for rejecting a heater assembly that is outof specification.

In at least one example embodiment of a manufacturing process, theequipment automatically manufactures a heater assembly from a meshstrip, a tin foil strip, and from plastic granules. The heater assemblycomprises a cap and a substantially flat electrically conductive heatingelement.

A method of manufacturing according to at least one example embodimentmay comprise a manual loading of at least one of a mesh strip bobbin, atin foil strip bobbin, and plastic granules. The method may furthercomprise at least one of the method steps that are automaticallyexecuted by the manufacturing equipment. The method may includeproviding a mesh strip, the mesh strip comprising an alternatingsequence of mesh sections of a first mesh density and of a second meshdensity, providing a tin foil strip, indexing a length of tin foil to bepositioned over the mesh section of the second mesh density, cutting tinpatches from the provided tin foil strip, compressing to join the tinpatches onto the top surface of the mesh section of the second meshdensity, and die cutting bevelled window slots out of each side of amesh section of the first mesh density. The method may also includeremoving loose wires from the cut mesh sections of the first meshdensity, small particles, dust, or debris by cleaning with air pressureand vacuuming the surfaces of the cut mesh sections to remove debris,pre-heating plastic granules, injecting the plastic granules into a moldfor making the cap, over-molding the cap onto the underside of a meshsection of the second mesh density, and cutting the heater assembly offthe mesh strip by die cutting a mesh off the mesh strip. The heatingelement comprises the mesh, and the mesh is cut within a mesh section ofthe second mesh density, such that the mesh comprises a mesh section ofthe first mesh density that is limited by mesh sections of the secondmesh density on each of the two ends of the cut mesh. The method mayalso include removing loose wires from the mesh, small particles, dust,or debris by cleaning with air pressure and vacuuming the surfaces ofthe mesh to remove debris, transporting the heater assembly to aninspection station, and measuring the electrical resistance of the meshof the manufactured heater assembly. The method may also includevisually inspecting the heater assembly for correct wire count, cleancut-off of the mesh, correct mesh integrity, debris and tin foilattachment, and rejecting the heater assembly if it is out ofspecification.

Features described in relation to one example embodiment may equally beapplied to other example embodiments.

At least one example embodiment relates to a heater assembly.

In at least one example embodiment, as shown in FIG. 1A, a heaterassembly 10 comprises a cap 12 with a first cap opening 16 on the topside of the cap and a second cap opening 18, shown in FIGS. 2A, 2B, and2C, on the bottom side of the cap 12. The first cap opening 16 iscovered by a holder 28 with a holder opening 30. The heater assembly 10further comprises a heating element 20 which extends across the holderopening 30.

FIG. 1B shows the heating assembly 10 from a bottom view. In at leastone example embodiment, the interior space of the hollow body 14 of thecap 12 becomes visible.

FIG. 1C shows the components of the heating element 20 comprising a mesh32. The mesh 32 has a first mesh section 44 of a first mesh density and,on each of its two extremities, a second mesh section 46 of a secondmesh density, wherein the second mesh density is higher than the firstdensity. A tin foil patch 50 is joined with each of the two meshsections 46 of the second mesh density. The heating element 20,respectively its mesh 32, is arranged across the holder opening 30 ofthe holder 28 on top of the cap 12. The entire mesh section 44 of thefirst mesh density is arranged above the holder opening 30.

FIG. 2A is a top view of the cap 12 and its holder 28. The holder 28 maybe a separate part. In at least one example embodiment, the holder 28 isan integral part of the cap 12. The interior body of the hollow body 14of the cap 12 is of cylindrical shape. The cuts A-A and B-B of FIG. 2Aare shown in FIGS. 2B-2D, respectively. The cap 12 and the holder 28 areintegrally formed, wherein the perspective view of FIG. 2D shows holder28 as a separate part. FIGS. 2B and 2C show the first cap opening 16which is partially closed by holder 28 so that only a smaller portion,referred to as holder opening 30, of the first cap opening 16 remainsopen and across which a heating element may extend.

FIG. 3 shows the holder 28 formed as a separate part of cap 12, whereinthe heating element 20 is mounted such that the mesh section 44 of thefirst mesh density extends across the holder opening 30.

FIG. 4 shows a mesh 32 of the heating element 20. The mesh 32 comprisesa mesh section 44 of a first mesh density and, on each of its twoextremities, a second mesh section 46 of a second mesh density.

FIG. 5 shows a mesh strip 42 from which a number of meshes 32 may be diecut.

FIG. 6 shows a cartridge 40 according to at least one exampleembodiment. The cartridge 40 comprises the heater assembly 10 with a cap12 and a heating element 20 arranged on a holder 28 of the cap 12. Atransport material piece 26 is arranged in a holder opening 30 of theholder 28. A host material piece 24 is arranged in the interior space ofthe hollow body 14 of the cap 12. The cap 12 acts as a rigid housing forthe transport material piece 26 and the host material piece 24. Thecartridge 40 further comprises a liquid storage portion 36 configured tostore a liquid aerosol-forming substrate. A retainer 52 is configured toretain the components of the heater assembly 10 and to keep the heaterassembly 10 in contact with the liquid storage portion 36 via thetransport material piece 26 and the host material piece 24. Furthermore,the cartridge 40 comprises a mouth piece 38 in which the liquid storageportion 36 is arranged.

FIG. 7 is a schematic illustration of an aerosol-generating systemaccording to at least one example embodiment.

In at least one example embodiment, as shown in FIG. 7, theaerosol-generating system may include a main unit 100 and the cartridge40. The main unit may include a power supply 105, control circuitry 110,and a sensor 115.

The exemplary embodiments described above illustrate but are notlimiting. In view of the above discussed exemplary embodiments, otherembodiments consistent with the above exemplary embodiments will now beapparent to one of ordinary skill in the art.

We claim:
 1. A heater assembly for an aerosol-generating system, theheater assembly being fluid permeable, the heater assembly comprising: acap including, a hollow body having a first cap opening and a second capopening, the first cap opening being opposite the second cap opening,the cap being integrally formed, and a holder including a holderopening, the holder configured to cover the first cap opening such thatthe holder opening superposes with at least a portion of the first capopening, the cap and the holder being integrally formed; a heatingelement, the heating element being a flat electrically conductive andfluid permeable heating element, the heating element configured tovaporize an aerosol-forming substrate, and the heating element mountedon the holder such that the heating element extends across the first capopening, and the heating element including, a mesh including at leasttwo electrically conductive contact areas, each of the at least twoelectrically conductive contact areas positioned at an edge area of theheating element, the mesh extending across at least a portion of thefirst cap opening, and the mesh covering an area of 30% to 90% of anopen area of the first cap opening; and a host material piece includinga wicking material, the host material piece configured to retain theaerosol-forming substrate, at least a portion of the host material piecearranged in the hollow body between the first cap opening and the secondcap opening, the host material piece at least partially in contact withthe heating element.
 2. The heater assembly according to claim 1,wherein the host material piece is substantially a same size and a sameshape as an interior space of the hollow body.
 3. The heater assemblyaccording to claim 1, wherein an interior space of the hollow body has asubstantially cylindrical shape.
 4. The heater assembly according toclaim 1, further comprising: a transport material piece configured totransport the aerosol-forming substrate from the host material piece tothe heating element, the transport material piece in contact with theheating element, the transport material piece between the heatingelement and the host material piece, and the heating element mounted onthe holder.
 5. The heater assembly according to claim 4, wherein thetransport material piece is in the holder opening.
 6. The heaterassembly according to claim 4, wherein the transport material piece hassubstantially a same size and a same shape as the holder opening.
 7. Theheater assembly according to claim 1, wherein the at least twoelectrically conductive contact areas are at a dense area of the heatingelement.
 8. The heater assembly according to claim 1, wherein theheating element includes a mesh strip.
 9. The heater assembly accordingto claim 4, wherein the transport material includes a wicking material.10. The heater assembly according to claim 1, wherein the mesh covers anarea of 50% to 70% of an open area of the first cap opening.
 11. Theheater assembly according to claim 1, wherein the mesh covers an area of55% to 65% of an open area of the first cap opening.
 12. The heaterassembly according to claim 1, wherein an electrical resistance of themesh ranges from 0.3 Ohms to 4 Ohms.